Modeling and estimation of the cardiac electromechanical activity

{\it Computers \& Structures}, in pressWe describe an approach that we propose to model the electromechanical behavior of the heart, and to use the model in a data assimilation procedure in order to perform an identification of the parameters and state. The modeling of the heart tissue is based on an electrically-activated contraction law formulated via multiscale considerations and is consistent with various physiological and thermomechanical key requirements. The global heart system also incorporates a simplified lumped modeling of the blood compartments. We report on numerical simulations and on validations of our model in reference and pathological conditions. Furthermore, the data assimilation procedure is intended to give access to quantities of interest for diagnosis purposes, and we present some promising results in this direction

Selective Expression of the Vβ14 T Cell Receptor on Leishmania guyanensis-Specific CD8+ T Cells during Human Infection

Peripheral blood mononuclear cells from subjects never exposed to Leishmania were stimulated with Leishmania guyanensis. We demonstrated that L. guyanensis-stimulated CD8+ T cells produced interferon (IFN)-γ and preferentially expressed the Vb14 T cell receptor (TCR) gene family. In addition, these cells expressed cutaneous lymphocyte antigen and CCR4 surface molecules, suggesting that they could migrate to the skin. Results obtained from the lesions of patients with localized cutaneous leishmaniaisis (LCL) showed that Vβ14 TCR expression was increased in most lesions (63.5%) and that expression of only a small number of Vb gene families (Vβ1, Vβ6, Vβ9, Vβ14, and Vβ24) was increased. The presence of Vβ14 T cells in tissue confirmed the migration of these cells to the lesion site. Thus, we propose the following sequence of events during infection with L. guyanensis. After initial exposure to L. guyanensis, CD8+ T cells preferentially expressing the Vb14 TCR and secreting IFN-γ develop and circulate in the periphery. During the infection, these cells migrate to the skin at the site of the parasitic infection. The role of these Vβ14 CD8+ T cells in resistance to infection remains to be determined conclusivel

In Leishmaniasis due to Leishmania guyanensis infection, distinct intralesional interleukin-10 and foxp3 mRNA expression are associated with unresponsiveness to treatment

The presence of intralesional natural regulatory T cells, characterized by the expression of Foxp3 mRNA, was analyzed in patients with localized leishmaniasis due to Leishmania guyanensis infection that was unresponsive to treatment with pentamidine isethionate. Foxp3 mRNA levels were associated with unresponsiveness to treatment among patients with a lesion duration of ⩾1 month, but this association was not observed among patients with a lesion duration of <1 month. In conclusion, high intralesional expression of Foxp3 might be an indicator of poor response to treatment, depending on the duration of lesion

A poroelastic model valid in large strains with applications to perfusion in cardiac modeling

National audienceSee http://hal.archives-ouvertes.fr/docs/00/59/26/88/ANNEX/r_5H9QH1SR.pd

Identité et abandon scolaire selon le genre en milieu collégial rapport de recherche /

La présente recherche a été subventionnée par le ministère de l'Éducation, du Loisir et du Sport dans le cadre du Programme d'aide à la recherche sur l'enseignement et l'apprentissage (PAREA)Également disponible en version papier.Titre de l'écran-titre (visionné le 28 août 2012

Identité et abandon scolaire selon le genre en milieu collégial article de vulgarisation /

La présente recherche a été subventionnée par le ministère de l'Éducation, du Loisir et du Sport dans le cadre du Programme d'aide à la recherche sur l'enseignement et l'apprentissage (PAREA)Également disponible en version papier

Joint state and parameter estimation for distributed mechanical systems

We present a novel strategy to perform estimation for a dynamical mechanical system in standard operating conditions, namely, without ad hoc experimental testing. We adopt a sequential approach, and the joint state-parameter estimation procedure is based on a state estimator inspired from collocated feedback control. This type of state estimator is chosen due to its particular effectiveness and robustness, but the methodology proposed to adequately extend state estimation to joint state-parameter estimation is general, and - indeed -applicable with any other choice of state feedback observer. The convergence of the resulting joint estimator is mathematically established. In addition, we demonstrate its effectiveness with a biomechanical test problem defined to feature the same essential characteristics as a heart model, in which we identify localized contractility and stiffness parameters using measurements of a type that is available in medical imaging

Staphylococcal Panton-Valentine Leucocidin as a Major Virulence Factor Associated to Furuncles

Panton-Valentine Leucocidin (PVL), one of the β-barrel pore-forming staphylococcal leucotoxins, is known to be associated to furuncles and some severe community pneumonia. However, it is still uncertain how many other virulence factors are also associated to furuncles and what the risk factors of furuncles are in immuno-compromised status of patients, especially the HIV (+) patients. In this paper, we use antigen immunoprecipitation and multiplex PCR approach to determine the presence of 19 toxins, 8 adhesion factors and the PFGE profiles associated to furuncles in three independent patient study groups of S. aureus (SA) isolates collected from the Cayenne General Hospital (French Guiana). The patient groups were made of: 16 isolates from HIV (−) patients, 9 from HIV (+) patients suffering from furuncles, and 30 control isolates from patients with diverse secondary infected dermatitis. Our data reveals that the majority (96%) of SA strains isolated from HIV patient-derived furuncles significantly produced PVL (p<10−7), whereas only 10% of SA strains produced this toxin in secondary infected dermatosis. A high prevalence of LukE-LukD-producing isolates (56 to 78%) was recorded in patient groups. Genes encoding clumping factor B, collagen- and laminin-binding proteins (clfB, cna, lbp, respectively) were markedly frequent (30 to 55%), without being associated to a specific group. Pulse field gel electrophoresis evidenced 24 overall pulsotypes, whereas the 25 PVL-producing isolates were distributed into 15 non clonal fingerprints. These pulsotypes were not specific PVL-producing isolates. PVL appears to be the major virulence factor associated to furuncles in Europe and in South America regardless of the immune status of the HIV patients

A Solve-RD ClinVar-based reanalysis of 1522 index cases from ERN-ITHACA reveals common pitfalls and misinterpretations in exome sequencing

Purpose Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the “ClinVar low-hanging fruit” reanalysis, reasons for the failure of previous analyses, and lessons learned. Methods Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. Results We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). Conclusion The “ClinVar low-hanging fruit” analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock